Microelectronic packages are commonly produced to contain two or more multi-axis sensors, such as a three axis Microelectromechanical Systems (MEMS) accelerometer and a three axis MEMS gyroscope. The transducer structures for the MEMS accelerometer and the MEMS gyroscope may be formed on a single die in a side-by-side relationship. A cap piece lacking active circuitry (commonly referred to as a “dummy cap”) may be bonded to the frontside of the die to form a hermetically-sealed cavity enclosing the accelerometer and gyroscope transducer structures. A known pressure is sealed within the hermetic cavity to improve the performance of the MEMS transducer structures. However, such a single cavity design generally requires that the accelerometer and gyroscope transducer structures are exposed to a common pressure. This can be disadvantageous as the optimal pressure at which the accelerometer structure operates may differ as compared to the optimal pressure at which the gyroscope transducer structure operates. Thus, exposing these disparate MEMS transducer structures to a single pressure may require a trade-off or compromise in the performance of at least one of the MEMS devices. As a further drawback, the formation of the accelerometer and gyroscope transducer structures in a side-by-side relationship on a single die may enlarge the overall planform dimensions of the microelectronic package.
It is thus desirable to provide embodiments of a microelectronic package including at least two MEMS transducer structures, such as accelerometer and gyroscope transducer structures, which are enclosed in fluidly-isolated hermetic cavities. In this manner, a different pressure may be sealed within each hermetic cavity to optimize the performance of the particular MEMS transducer structure enclosed thereby. Ideally, embodiments of such a microelectronic package would also be structurally robust and have relatively compact planform dimensions. It would also be desirable to provide embodiments of a method for fabricating microelectronic packages having one or more of the foregoing characteristics. Other desirable features and characteristics of embodiments of the present invention will become apparent from the subsequent Detailed Description and the appended Claims, taken in conjunction with the accompanying drawings and the foregoing Background.
For simplicity and clarity of illustration, the drawing figures illustrate the general manner of construction, and descriptions and details of well-known features and techniques may be omitted to avoid unnecessarily obscuring the exemplary and non-limiting embodiments of the invention described in the subsequent Detailed Description. It should further be understood that features or elements appearing in the accompanying figures are not necessarily drawn to scale unless otherwise stated. For example, the dimensions of certain elements or regions in the figures may be exaggerated relative to other elements or regions to improve understanding of embodiments of the invention.